Potential of Sumilink-200 was investigated in a typical natural rubber-based tread compound in connection with its ability to act as a coupling agent for carbon black to reduce hysteresis loss of the compound. Optimum physical properties were obtained at 2 phr loading of Sumilink-200. At this loading, tensile modulus at 300% elongation improved by 9.6% with a reduction in visco-elastic energy dissipation (loss tangent) at 60°C by 8.3% over the control compound. The abrasion resistance properties of the compounds found to remain unaffected with the introduction of Sumilink-200.

Proficiency on underlying mechanism of rubber‐metal adhesion has been increased significantly in the last few decades. Researchers have investigated the effect of various ingredients, such as hexamethoxymethyl melamine, resorcinol, cobalt stearate, and silica, on rubber‐metal interface. The role of each ingredient on rubber‐metal interfacial adhesion is still a subject of scrutiny. In this article, a typical belt skim compound of truck radial tire is selected and the effect of each adhesive ingredient on adhesion strength is explored. Out of these ingredients, the effect of cobalt stearate is found noteworthy. It has improved adhesion strength by 12% (without aging) and by 11% (humid‐aged), respectively, over control compound. For detailed understanding of the effect of cobalt stearate on adhesion, scanning electron microscopy and energy dispersive spectroscopy are utilized to ascertain the rubber coverage and distribution of elements. X‐ray photoelectron spectroscopy results helped us to understand the impact of CuXS layer depth on rubber‐metal adhesion. The depth profile of the CuXS layer was found to be one of the dominant factors of rubber‐metal adhesion retention. Thus, this study has made an attempt to find the impact of different adhesive ingredients on the formation of CuXS layer depth at rubber‐metal interface and establish a correlation with adhesion strength simultaneously.

Physico-mechanical and dynamic mechanical properties of typical solution grade styrene-butadiene rubber (S-SBR) and polybutadiene rubber (PBR) based tiretread compound were investigated by partially replacing highly dispersible (HD) silica with naturally occurring α-cellulose. Fourier transform infrared spectrum detected abundance of hydroxyl group in α-cellulose, which has created keenness to investigate its reinforcement characteristics in an S-SBR and PBR based compound. Scanning electron microscope and transmission electron microscope were employed to investigate the microstructure and dispersion of α-cellulose at higher magnification. Thermo-gravimetric analysis was performed to understand the degradation behavior of α-cellulose. Differential scanning calorimeter was engaged to detect phase transition and degree of purity of α-cellulose. An increase in cure rate was observed with partial replacement of HD silica by α-cellulose. The cure rate index was increased by 13% over control one at 10% replacement of silica with α-cellulose. It was noticed that at an optimum level of replacement (10%), α-cellulose containing compounds exhibited lower viscoelastic energy dissipation (both loss modulus [E 00 ] and loss tangent [tan δ]) at the slight expense of tensile moduli. Beside these, substitution of silica with α-cellulose found to have no effect on wet grip property of the compounds.

Rubber products, especially tire, experiences millions of fatigue cycles during their service life. In this period, penetration or cuts owing to any sharp objects brings calamitous failure. Thus, the fatigue crack growth (FCG) characteristic of tire components has become an important parameter to inspect. In the present study, the FCG behavior of sustainable filler, lignin‐filled composite is investigated. The impact of rubber matrix (epoxidation of natural rubber) on crack growth behavior is scrutinized in this article. Epoxy group introduction in natural rubber leads to a significant change in tearing energy throughout the strain range (10%–25%). Higher mol% of the epoxy group brings in a lower crack growth rate. An increase in polar interaction amongst the matrix through epoxide—hydroxyl functionality contributes significantly to the FCG rate. Inter‐molecular interaction promotes higher cross‐link density in epoxidized natural rubber containing composites which are reflected in static as well as dynamic‐mechanical properties. Morphological evidence (Field‐emission scanning electron microscope [FE‐SEM] and microscopic images) establishes the fact that stiffening at the crack tip, arising from intrinsic strain‐induced crystallization and high‐density network formation in the concerned matrix are the major contributors to the reduction in fatigue crack growth rate of a composite.

In the current context of green mobility and sustainability, the use of new generation natural fillers, namely, α-cellulose, has gained significant recognition. The presence of hydroxyl groups on α-cellulose has generated immense eagerness to map its potency as filler in an elastomeric composite. In the present work, α-cellulose-emulsion-grade styrene butadiene rubber (E-SBR) composite is prepared by conventional rubber processing method by using variable proportions of α-cellulose (1 to 40 phr) to assess its reinforce ability. Rheological, physical, visco-elastic and dynamic-mechanical behavior have clearly established that 10 phr loading of α-cellulose can be considered as an optimized dosage in terms of performance parameters. Morphological characterization with the aid of scanning electron microscope (SEM) and transmission electron microscopy (TEM) also substantiated that composite with 10 phr loading of α-cellulose has achieved the morphological threshold. With this background, synthetic filler (silica) is substituted by green filler (α-cellulose) in an E-SBR-based composite. Characterization of the compound has clearly established the reinforcement ability of α-cellulose.